Height adjustment structure

ABSTRACT

A height adjustment structure for an image-scanning device. The scanning device has a guiding rod, an optical system and a document panel. The guiding rod and the document panel are fixed relative to each other. The optical system includes a box body and an axial rod bearer that can slide along into the guiding rod. The height adjustment structure includes a first positioning section and a second positioning section. The first positioning section is attached to one side of the box body and the second positioning section is attached to one side the axial rod bearer that faces the first positioning section. The first positioning section and the second positioning section has hooking mechanism, screwing mechanism or teeth-meshing mechanism for fixing the box body relative to the axial rod bearer and hence setting the distance from the box body to the document panel.

BACKGROUND OF THE INVENTION

1. Field of Invention

The present invention relates to a height adjustment structure. Moreparticularly, the present invention relates to a height adjustmentstructure inside a scanning device for adjusting distance of separationbetween an optical system and a document holder panel.

2. Description of Related Art

As a result of the rapid advances in multimedia software, networkconnection and computer technologies, the scanner has become anindispensable peripheral device for a computer system. In general, aplatform-type scanner includes an optical system and a driving device.Through the driving device, the chassis housing the optical system isdriven so that a sensor in the optical system may scan the image on adocument in steps and turn the scanned image into electronic signals.Normally, the optical sensor is a charge-coupled device (CCD).

FIG. 1 is a perspective view showing a guiding rod, a driving device andan optical system in a conventional platform-type scanner. FIG. 2 is aside view of the document holder, the guiding rod and the optical systemin the conventional platform-type scanner. As shown in FIG. 1, a lightsource 12 and a slit 14 are positioned over the optical system 10. Lightfrom the light source 12 penetrates a transparent document panel 40 toarrive at the surface of a document 50. After reflection, the reflectedlight passes through the slit 14 and enters the optical system 10 forimage processing. By driving transmission device 20 forward slowly, theoptical system 10 advances in steps until the entire document 50 isscanned.

Since the optical system 10 must advance in a preset direction linearlywith precision to avoid image distortion, the optical system 10 needs tofollow a guiding rod 30. Hence, the chassis that houses the opticalsystem has a positioning hole 16 for sliding along the guiding rod 30.As shown in FIG. 2, the transmission device 20 drives one side of thechassis. Therefore, a roller 18 is installed on the other side of thechassis so that the document 50 on the panel 40 can move in parallel andprevent any tilting of the optical system 10.

In general, an optical system includes a light source, a reflectingmirror, transparent lenses and an optical sensor. All these componentsare housed inside a chassis. Hence, for similar design, the lens insidethe optical system must have a fixed object distance. However, fordifferent types of platform scanner design, distance 42 from thedocument panel 40 to the guiding rod 30 may be slightly different.Consequently, distance 44 from the optical system 10 to the documentpanel 40 needs to be adjusted so that the document 50 is in proper focuswith respect to the object distance of the lens system (not shown)inside the optical system 10. In other words, the distance from thedocument panel 40 to the lens inside the optical system 10 must beproperly set in each design. Since the distance must be carefully setfor each scanner design, production and design cost are greatlyincreased.

SUMMARY OF THE INVENTION

Accordingly, one object of the present invention is to provide a heightadjustment structure. Height adjustment is achieved by redesigning theexternal housing of the optical system. The housing comprises twoseparate units including a box body and an axial rod bearer such thatdistance between the box body and the document panel can be adjusted tomatch different type of platform design.

To achieve these and other advantages and in accordance with the purposeof the invention, as embodied and broadly described herein, theinvention provides a height adjustment structure for an image scanningdevice. The structure can be roughly divided into a first positioningsection and a second positioning section on one side of the box body andthe axial rod bearer, respectively. The first and the second positioningsection may be engaged by a latching mechanism, screwing mechanism orteeth-lock mechanism. Relative distance from the box body of the opticalsystem to the axial rod bearer can be adjust by moving vertically beforefixing the two using any one of the aforementioned engaging mechanisms,thereby obtaining an optical distance of separation between the box bodyand the document panel.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary, and are intended toprovide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention. In the drawings,

FIG. 1 is a perspective view showing a guiding rod, a driving device andan optical system in a conventional platform-type scanner;

FIG. 2 is a side view of the document holder, the guiding rod and theoptical system in the conventional platform-type scanner;

FIG. 3 is a schematic cross-sectional diagram showing a heightadjustment structure according to this invention;

FIG. 4 is a schematic cross-sectional diagram showing a heightadjustment structure according to a first embodiment of this invention;

FIG. 5 is a schematic cross-sectional diagram showing an alternativeheight adjustment structure according to the first embodiment of thisinvention;

FIG. 6 is a schematic cross-sectional diagram showing a heightadjustment structure according to a second embodiment of this invention;

FIG. 7 is a schematic cross-sectional diagram showing a heightadjustment structure according to a third embodiment of this invention;

FIG. 8 is a schematic cross-sectional diagram showing a screw-lockmechanism used by the height adjustment structure in FIG. 7; and

FIG. 9 is a schematic top view of a latching mechanism for fixing therelative position between the first and the second positioning sectionsin a height adjustment according to the third embodiment of thisinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the present preferredembodiments of the invention, examples of which are illustrated in theaccompanying drawings.

Wherever possible, the same reference numbers are used in the drawingsand the description to refer to the same or like parts.

To adjust the distance between the optical system and the document panel(as shown in FIG. 2), a height adjustment structure is introduced inthis invention. FIG. 3 is a schematic cross-sectional diagram showing aheight adjustment structure according to this invention. As shown inFIG. 3, an optical system 10 structure comprises two major parts, a boxbody 13 and an axial rod bearer 15. The box body 13 houses the majorcomponents of the optical system 10 including, for example, a lightsource, a set of reflecting mirrors, a set of lenses, an optical sensorand so on. The axial rod bearer 15 includes a positioning hole 16 intowhich is slid a guiding rod 30 such as the one shown in FIGS. 1 and 2.Driven by a transmission device 20, the axial rod bearer 15 moves alongthe axis of the guiding rod 30 linearly and horizontally. In addition,the height adjustment structure 100 also includes a first positioningsection 110 and a second positioning section 120. The first positioningsection 110 is attached to one side of the box body 13 and the secondpositioning section 120 is attached to a corresponding side of the axialrod bearer 15. The first position section 110 and the section positionsection 120 may move vertically up or down before being fixed relativeto each other by a locking mechanism such as a latching structure, ascrewing structure or a teeth-engage structure. In this invention, thefirst embodiment illustrates a latching structure, the second embodimentillustrates a screwing structure and the third embodiment illustrates ateeth-engage structure.

FIG. 4 is a schematic cross-sectional diagram showing a heightadjustment structure according to a first embodiment of this invention.The first positioning section 130 is mounted on the side of the box body13 that corresponds to the axial rod bearer 15. The first positioningsection 130 has a plurality of plugging slots 132 each having anopening. The plugging slots 132 are located on the exterior facing sideof the first positioning section 130 and laid along the verticaldirection from bottom to top. The second positioning section 140 ismounted on the side of the axial rod bearer 15 that corresponds to thebox body 13. The second positioning section 140 has a gripping hook 142that can engage with one of the plugging slots 132 on the firstpositioning section 130. The first positioning section 130 and the boxbody 13 may be fabricated together as a single component or lockedtogether with screws. Similarly, the second positioning section 140 andthe axial rod bearer 15 may be fabricated together as a single componentor may be locked together with screws.

As shown in FIGS. 2 and 4, distance from the guiding rod 30 to thedocument panel 40 is normally fixed. If the hook 142 engages with aplugging slot 132 in the lower portion of the first positioning section130, the box body 13 is raised, thereby shortening the distance 44 fromthe optical system 10 to the document panel 40. Conversely, if the hook142 engages with a plugging slot 132 in the upper portion of the firstpositioning section 130, the box body 13 is lowered thereby increasingthe distance 44 from the optical system 10 to the document panel 40. Inthe meantime, the roller 18 or height of the underside 60 must beadjusted to match the adjusted box body 13 so that tilting of the boxbody 13 is prevented.

Hence, by plugging the hook 142 into different plugging slots 132,relative distance 44 in the vertical direction between the box body 13and the axial rod bearer 15 can be adjusted. Ultimately, surface of adocument 50 falls on the exact object distance of the internal lenses(not shown) inside the optical system 10. Thus, there is no need toredesign the assembly once another type of optical system is installed.In addition, manual assembly of the box body 13 with the axial rodbearer 15 is very much simplified and assembling speed is therebyincreased because the hook 142 may engage into a specific plugging slot132 for each type of optical system.

FIG. 5 is a schematic cross-sectional diagram showing an alternativeheight adjustment structure according to the first embodiment of thisinvention. As shown in FIG. 5, the second positioning section 140 of theheight adjustment structure 100 has two or more hooks 144 that can beplugged into some of the plugging slots 136 for a higher structuralstrength. In addition, the number of plugging slots 136 can also beincreased to extend the range of adjustment of the box body 13.Moreover, the first positioning section 130 may mount on the side of theaxial rod bearer 15 so that the second positioning section 140 nowmounts on the side of the box body 13. In other words, the location ofthe first positioning section 130 and the second positioning section 140may be reversed without affecting the height adjusting capacity of thestructure 100.

FIG. 6 is a schematic cross-sectional diagram showing a heightadjustment structure according to a second embodiment of this invention.As shown in FIG. 6, the height adjustment structure 200 comprises afirst positioning section 210, a second positioning section 220 and alocking screw 230. The first positioning section 210 is attached to oneside of a box body 13 facing an axial rod bearer 15. The secondpositioning section 220 is attached to one side of the axial rod bearer15 facing the box body 13. The first positioning section 210 includes atleast one threaded hole 212 having a central axis aligned in a directionperpendicular to the document panel 40 (as shown in FIG. 2). The secondpositioning section 220 includes at least a through hole 222 that alignswith the axis of the threaded hole 212. In addition, at least onelocking screw 230 is provided. The locking screw 230 passes through thethrough hole 222 and screws into the threaded hole 212. The firstpositioning section 210 and the box body 13 may be fabricated togetheras a single component or locked together with screws. Similarly, thesecond positioning section 220 and the axial rod bearer 15 may befabricated together as a single component or lock together with screws.

As shown in FIGS. 2 and 6, distance from the guiding rod 30 to thedocument panel 40 is normally fixed. If the screw 230 screws deeper intothe threaded hole 212, the box body 13 is raised, thereby shortening thedistance 44 from the optical system 10 to the document panel 40.Conversely, if the amount of screwing of the screw 230 into the threadedhole 212 is reduced, the box body 13 is lowered, thereby increasing thedistance 44 from the optical system 10 to the document panel 40. In themeantime, the roller 18 or height of the underside 60 must be adjustedto match the adjusted box body 13 so that tilting of the box body 13 isprevented.

Hence, by adjusting the screwing depth of the screw 230 into thethreaded hole 212, relative distance 44 in the vertical directionbetween the box body 13 and the axial rod bearer 15 can be adjusted.Ultimately, surface of a document 50 falls on the exact object distanceof the internal lenses (not shown) inside the optical system 10. Thus,there is no need to redesign the assembly once another type of opticalsystem is installed. In addition, since the pitch of the thread on thescrew 130 is usually small, height level of the box body 13 may be moreprecisely adjusted.

Furthermore, to increase the vertical adjusting range of the box body13, a longer threaded screw 230 may be used. Moreover, the firstpositioning section 210 may mount on the side of the axial rod bearer 15so that the second positioning section 220 now mounts on the side of thebox body 13. In other words, the location of the first positioningsection 210 and the second positioning section 220 may be reversedwithout affecting the height adjusting capacity of the structure 200.

FIG. 7 is a schematic cross-sectional diagram showing a heightadjustment structure according to a third embodiment of this invention.As shown in FIG. 7, the height adjustment structure 300 comprises afirst positioning section 310, a second positioning section 320 and anengaging component 330. The first positioning section 310 is attached toone side of a box body 13 facing an axial rod bearer 15. The secondpositioning section 320 is attached to one side of the axial rod bearer15 facing the box body 13. The first positioning section 310 has a firstset of teeth 312. The first set of teeth 312 protrudes from the firstpositioning section 310 away from the side along a vertical line. Thesecond positioning section 320 has a second set of teeth 322 thatmatches the shape of the first set of teeth 312 and similarly protrudesfrom one side of the second positioning section 320. Since the first andthe second set of teeth have matching profile, the first set of teeth312 can mesh with the second set of teeth 322 and fix the firstpositioning section 310 and the second positioning section 320 relativeto each other.

Reference is made to FIG. 8 in describing how the first positioningsection 310 is fixed relative to the second positioning section 320,refer to FIG. 8. FIG. 8 is a schematic cross-sectional diagram showing ascrew-lock mechanism used by the height adjustment structure in FIG. 7.After the teeth in first positioning section 310 and the teeth in thesecond positioning section 320 are engaged according to a set position,a screw 330 running in a vertical direction perpendicular to directionof the first and second set of teeth is used as a fixing element. Thescrew 330 locks up the first positioning section 310 and the secondpositioning section 320, thereby fixing their relative locations.

FIG. 9 is a schematic top view of a latching mechanism for fixing therelative position between the first and the second positioning sectionsin a height adjustment according to the third embodiment of thisinvention. To fix the relative position of the first positioning section310 and the second positioning section 320, a pair of latching elements340 is used The pair of latching elements 340 is a latching block 342and a latching hook 344. The latching block 342 protrudes from the sidesof the first positioning section 310 perpendicular to the protrudingdirection of the first set of teeth 312. The latching hooks 344 alsoprotrudes from the sides of the second positioning section 320perpendicular to the protruding direction of the second set of teeth322. Therefore, after finding a suitable engagement position forengaging the first set of teeth 312 and the second set of teeth 322, thelatching hooks 344 click onto the latching blocks 342. Hence, positionof the first positioning section 310 relative to the second positioningsection 320 of the height adjustment structure is locked.

As shown in FIGS. 2 and 7, distance from the guiding rod 30 to thedocument panel 40 is normally fixed. If the second set of teeth 322meshes with the teeth near the bottom section of the first set of teeth312, the box body 13 is raised thereby shortening the distance 44 fromthe optical system 10 to the document panel 40. Conversely, if thesecond set of teeth 322 meshes with the teeth near the top section ofthe first set of teeth 312, the box body 13 is lowered therebyincreasing the distance 44 from the optical system 10 to the documentpanel 40. In the meantime, the roller 18 or height of the underside 60must be adjusted to match the adjusted box body 13 so that tilting ofthe box body 13 is prevented.

Hence, by adjusting the meshing position of the teeth between the firstset of teeth 312 and the second set of teeth 322, relative distance 44in the vertical direction between the box body 13 and the axial rodbearer 15 can be adjusted. Ultimately, surface of a document 50 falls onthe exact object distance of the internal lenses (not shown) inside theoptical system 10. Thus, there is no need to redesign the assembly onceanother type of optical system is installed. In addition, if the pitchof the engaging teeth is small, height level of the box body 13 can beadjusted more precisely. Furthermore, to increase vertical adjustingrange of the box body 13, the total number of teeth in the first set ofteeth 312 may be increased. Moreover, the first positioning section 310may mount on the side of the axial rod bearer 15 so that the secondpositioning section 320 now mounts on the side of the box body 13. Inother words, the location of the first positioning section 310 and thesecond positioning section 320 may be reversed without affecting theheight adjusting capacity of the structure 300.

In conclusion, major advantages of the height adjustment structure ofthis invention include:

-   -   1. The height adjustment structure can accommodate different        types of platform scanner design so that identical optical        system may be employed in different modular platform design.    -   2. The first embodiment of this invention uses a latching        hook/plugging slot design. By setting the latching hook to        engage with a particular plugging slot. Manual assembly is very        much simplified, thereby boosting assembling speed.    -   3. The second embodiment of this invention uses a screw and a        threaded hole design. Since screw threads usually have a fine        pitch, distance from the document panel to the optical system        can be accurately adjusted.    -   4. The third embodiment of this invention uses sets of meshing        teeth to fix the position Since fine meshing teeth are usually        used, height adjustment can be very precise.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of the presentinvention without departing from the scope or spirit of the invention.In view of the foregoing, it is intended that the present inventioncover modifications and variations of this invention provided they fallwithin the scope of the following claims and their equivalents.

1. A height adjustment structure for a scanning device, wherein thescanning device includes an optical system, a document panel and aguiding rod, the optical system and the guiding rod are located underthe document panel and the document panel is fixed relative to theguiding rod, the optical system further includes a box body and an axialrod bearer, the axial rod bearer is on one side of the box body and theaxial rod bearer has a positioning hole whereinto the guiding rod isslid so that the optical system moves horizontally along an axialdirection of the guiding rod, the height adjustment structure is adevice for adjusting a relative position between the box body and theaxial rod bearer so that distance from the box body to the documentpanel is adjustable, the height adjustment structure comprising: a firstpositioning section attached to one side of the box body facing theaxial rod bearer, wherein the first positioning section has a pluralityof plugging slots having openings on an exterior surface and the slotsspreads out vertically; and a second positioning section attached to oneside of the axial rod bearer facing the box body, wherein the secondpositioning section has at least one hook protruding from an exteriorsurface such that the hook may plug into one of the slots in the firstpositioning section.
 2. The structure of claim 1, wherein the firstpositioning section and the box body are formed together as anintegrated unit.
 3. The structure of claim 1, wherein the secondpositioning section and the axial rod bearer are formed together as anintegrated unit.
 4. The structure of claim 1, wherein the firstpositioning section and the box body are locked together by screws. 5.The structure of claim 1, wherein the second positioning section and theaxial rod bearer are locked together by screws.
 6. A height adjustmentstructure for a scanning device, wherein the scanning device includes anoptical system, a document panel and a guiding rod, the optical systemand the guiding rod are located under the document panel and thedocument panel is fixed relative to the guiding rod, the optical systemfurther includes a box body and an axial rod bearer, the axial rodbearer is on one side of the box body and the axial rod bearer has apositioning hole whereinto the guiding rod is slid so that the opticalsystem moves horizontally in an axial direction of the guiding rod, theheight adjustment structure is a device for adjusting a relativeposition between the box body and the axial rod bearer so that distancefrom the box body to the document panel is adjustable, the heightadjustment structure comprising: a first positioning section attached toone side of the box body facing the axial rod bearer, wherein the firstpositioning section has at least a threaded hole having an axisperpendicular to the document panel; a second positioning sectionattached to one side of the axial rod bearer facing the box body,wherein the second positioning section has at least one through holehaving an axis aligned with the axis of the threaded hole; and at leastone screw that passes through the through hole and screws into thethreaded hole, wherein depth of the screw inside the threaded holedepends on a required distance between the box body and the axial rodbearer.
 7. The structure of claim 6, wherein the first positioningsection and the box body are formed together as an integrated unit. 8.The structure of claim 6, wherein the second positioning section and theaxial rod bearer are formed together as an integrated unit.
 9. Thestructure of claim 6, wherein the first positioning section and the boxbody are locked together by screws.
 10. The structure of claim 6,wherein the second positioning section and the axial rod bearer arelocked together by screws.
 11. A height adjustment structure for ascanning device, wherein the scanning device includes an optical system,a document panel and a guiding rod, the optical system and the guidingrod are located under the document panel and the document panel is fixedrelative to the guiding rod, the optical system further includes a boxbody and an axial rod bearer, the axial rod bearer is on one side of thebox body and the axial rod bearer has a positioning hole whereinto theguiding rod is slid so that the optical system moves horizontally alongthe axial direction of the guiding rod, the height adjustment structureis a device for adjusting a relative position between the box body andthe axial rod bearer so that distance from the box body to the documentpanel can be adjusted, the height adjustment structure comprising: afirst positioning section attached to one side of the box body facingthe axial rod bearer, wherein the first positioning section has a firstset of teeth protruding from one side face of the first positioningsection and panning out from bottom to top in a vertical direction; asecond positioning section attached to one side of the axial rod bearerfacing the box body, wherein the second positioning section has a secondset of teeth protruding from one side face of the second positioningsection and having a teeth profile matching the teeth in the first setso that relative position of the box body and the axial rod bearer isadjustable by meshing the second set at a suitable location with thefirst set; and a locking element that links up and fixes a position ofthe first positioning section relative to the second positioningsection.
 12. The structure of claim 11, wherein the first positioningsection and the box body are formed together as an integrated unit. 13.The structure of claim 11, wherein the second positioning section andthe axial rod bearer are formed together as an integrated unit.
 14. Thestructure of claim 11, wherein the first positioning section and the boxbody are locked together by screws.
 15. The structure of claim 11,wherein the second positioning section and the axial rod bearer arelocked together by screws.
 16. The structure of claim 11, wherein thelocking element includes a threaded screw and the threaded screwtightens up the first and the second positioning section together. 17.The structure of claim 11, wherein the locking element includes alatching unit, the latching unit comprises a pair of latching hooks anda pair of latching blocks attached to the sides of the first positioningsection and the second positioning section, respectively, wherein thelatching hooks click onto the latching blocks after a suitable positionfor engaging the first and the second set of teeth is found.